Metal-Organic Frameworks: A Robust Platform for Creating Nanoarchitectured Carbon Materials

CONSPECTUS: Nanoporous carbon (NPC) materials with various architectures have attracted considerable attention because of their distinctive properties and great application potential in environmental remediation, energy conversion and storage, advanced sensors, and other applications. Traditional methods for the synthesis of NPCs, for example, the pyrolysis of natural products or polymers, template-assisted synthesis, and using deep-eutectic solvents, always involve toxic precursors and complex procedures, which greatly hinder further applications. Therefore, it is highly desirable to explore simple and feasible ways to prepare NPCs. Furthermore, to improve the performance and extend the application fields of NPCs, efficient strategies should be developed to regulate the components at the atomic level and construct multidimensional architectures. Metal-organic frameworks (MOFs, also known as porous coordination polymers), which consist of metal ions or clusters and organic ligands, are a new class of porous hybrid materials with reticular structures. As a result, MOFs show interesting characteristics, such as large surface areas, tailored compositions, and structural diversity, which make them ideal platforms for creating functional NPCs. Although significant progress has been made in MOF-derived NPCs with different architectures since the first reported MOF-derived NPC in 2008, this is still an emerging field with inexhaustible potential. In this Account, we highlight the concepts and strategies of our research on MOF-derived NPCs with different architectures, including zero-dimensional (0D) nanopolyhedral, core-shell, and hollow structures, one-dimensional (1D) nanofibers and nanotubes, two-dimensional (2D) nanoflakes and graphene nanomeshes, and three-dimensional (3D) nanoarrays, carbon aerogels, and gradient monoliths. First, we briefly introduce the history of MOFs and discuss their advantages as a platform for the preparation of NPCs. We then summarize the methods for the synthesis of 0D-3D NPCs from MOFs with controllable morphology, composition, and structure. Commonly, two major preparation concepts are involved: direct carbonation of MOFs and pyrolysis of MOF composites. For MOF composites, we have developed (i) electrospinning, (ii) in situ growth, (iii) freeze-drying, and (iv) chemical vapor deposition synthetic strategies for the generation of novel hybrid materials. Additionally, we describe the conversion mechanisms and how to precisely control the architectures in detail. The relationship between the chemical and physical properties of the parent MOFs and derived NPCs is also discussed. The potential applications of MOF-derived NPCs in energy, environmental, and catalysis fields are also demonstrated. Finally, the prospects and challenges for using MOFs as a precursor for designing NPCs are discussed. We believe that this Account will accelerate the development of MOF-derived NPCs and inspire the design and preparation of novel carbon materials.

Automated summary

Nanoporous carbon materials have unique properties and great application potential in various fields. Metal-organic frameworks (MOFs) provide an ideal platform for the preparation of functional nanoporous carbons. This Account highlights the concepts, strategies, and synthesis methods of MOF-derived nanoporous carbons with different architectures, and discusses their potential applications in energy, environmental, and catalysis fields.